Choice of serum tumor markers in patients with small cell lung cancer: progastrin-releasing peptide, neuron-specific enolase, and carcinoembryonic antigen

An EGFR-mutant lung adenocarcinoma that transformed into small-cell lung cancer. A case report

BACKGROUND

Transformation of EGFR (epidermal growth factor receptor) - mutant non-small cell lung cancer (NSCLC) into small-cell lung cancer (SCLC) is one mechanism of resistance to tyrosine kinase inhibitor (TKI) treatment, seen in approximately 3-10% cases. Such transformed SCLC often retains the original EGFR mutation (EGFRM), which is not otherwise observed in SCLC.

CASE REPORT

We present a 67 y/o woman with pulmonary adenocarcinoma (AC) and EGFRM deletion on exon 19. After initial treatment with whole brain radiotherapy and 7 months of TKI afatinib, progression was observed. Liquid biopsy detected deletion on exon 19 and T790M mutation. Chemotherapy carboplatin plus pemetrexed was administered, with no response. Genetics from a rebiopsy of lung revealed deletion on exon 19. After 12 months treatment with TKI osimertinib, a progression in lung and pancreas lesions was detected, docetaxel was used, with followig progression. The lung biopsy revealed SCLC. Significant elevation of serum markers carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) was observed at the time of the SCLC diagnosis. Treatment with carboplatin and etoposide was not effective. The next biopsy found two populations of cells: SCLC and AC. The biopsy from the pancreatic lesion revealed metastasis of SCLC. PCR confirmed EGFRM deletion on exon 19 in the lung SCLC tissue sample. The following treatment lines of topotecan, erlotinib were not effective. The patient survived 36 months from diagnosis, 7 months from detection of SCLC.

CONCLUSION

Screening for transformation of EGFR-mutant NSCLC to SCLC should be considered in resistance to TKI. In the presented case, this rare transformation was confirmed by histopathologic examination and by PCR. EGFRM in the lung SCLC, identical to that found in the original lung AC, was detected. Further, the observed elevation of serum tumor markers NSE and CEA can indicate this infrequent transformation and help to decide on rebiopsy.

Potential of Stem Cells and CART as a Potential Polytherapy for Small Cell Lung Cancer

Despite the increasing urgency of the problem of treating small cell lung cancer (SCLC), information on the causes of its development is fragmentary. There is no complete understanding of the features of antitumor immunity and the role of the microenvironment in the development of SCLC resistance. This impedes the development of new methods for the diagnosis and treatment of SCLC. Lung cancer and chronic obstructive pulmonary disease (COPD) have common pathogenetic factors. COPD is a risk factor for lung cancer including SCLC. Therefore, the search for effective approaches to prevention, diagnosis, and treatment of SCLC in patients with COPD is an urgent task. This review provides information on the etiology and pathogenesis of SCLC, analyses the effectiveness of current treatment options, and critically evaluates the potential of chimeric antigen receptor T cells therapy (CART therapy) in SCLC. Moreover, we discuss potential links between lung cancer and COPD and the role of endothelium in the development of COPD. Finally, we propose a new approach for increasing the efficacy of CART therapy in SCLC.